BRUSSELS, Belgium - All eyes were on Brussels on Monday as the first full round of Brexit negotiations began, even as the U.K. government seems to be at war with itself over the divorce terms.

On Monday, Britain's Brexit minister pledged to "get down to work" as he kicked off the negotiations a year after Britons voted narrowly to leave the EU.

Anti-EU campaigner David Davis was welcomed by the bloc's chief negotiator Michel Barnier before their teams began four days of talks and said, "It's time to get down to work and make this a successful negotiation.”

Davis acknowledged it was "incredibly important" to make progress, "that we negotiate through this and identify the differences so that we can deal with them and identify the similarities so that we can reinforce them.”

Barnier meanwhile said, "We will now delve into the heart of the matter,” before the two sat down for a first meeting flanked by the officials who will lead the detailed negotiations.

Photos from the meeting table, however, were ridiculed by critical British commentators due to a lack of notes on the table in front of Davis and his two advisers.

However, sheaves of paperwork were seen in front of Barnier and his team.

Commentators saw it as an image of the government's failure to prepare for such a vital negotiation.

Davis later returned to London, leaving civil servants on both sides to engage in talks.

Barnier has dismissed the British rights offer as falling short of the EU demand that its 3 million citizens there keep all their existing rights for life and have recourse to the EU courts to enforce those rights even after Britain has left.

Barnier and Davis will brief the media on Thursday when they would give political endorsement to whatever officials have managed to agree.

According to reports, the groups are expected to focus on three issues, including citizens' rights; the EU demand that Britain pay some 60 billion euros ($69 billion) to cover ongoing EU budget commitments; and other loose ends.

Talks, run by Davis and Barnier's deputies Oliver Robbins and Sabine Weyand, will then focus on curbing problems in Northern Ireland once a new EU land border separates the British province from EU member Ireland to the south.

Meanwhile, in Britain, Prime Minister Theresa May’s authority was diminished after she lost her majority in the June election that she called.

Since then, May has struggled to control rival cabinet ministers, worrying European Union negotiators who stress that 20 months until Brexit is very little time to negotiate an orderly departure.

Further, British media was rife with reports of infighting between the Leave and Remain groups.

Foreign Secretary Boris Johnson, who also was in Brussels for a separate meeting, however, did not comment on whether ministers are at odds.

In June last year, his backing helped secure a four-point victory for the Leave camp.

When questioned whether the cabinet was still split on Brexit, Johnson said he was pleased that negotiations had begun and then defended the offer May has made to protect the rights of EU citizens in Britain.

EU officials have said that splits in London over basic issues, such as the need for a phased withdrawal lasting for some years, could raise the risk of a failure to reach any deal.

This would lead to huge uncertainty for businesses and millions of people across Europe as the U.K. would be out of the bloc on March 30, 2019 and there would be no clear rules on the future.

London and Brussels have said they are ready for such an outcome but most officials in Brussels believe Britain must be bluffing.

British businesses meanwhile are anxious to see a coherent approach to indicate how a transition would work.